This invention relates to the thermal insulation of containers for liquids. More specifically, it relates to means for keeping containers for potable liquids at a temperature below ambient. Potable liquids, such as soft drinks and beer, are commonly sold for consumption in thin walled metal cans. These are normally dispensed from refrigerated containers, or may be stored in a domestic refrigerator, but once they have been delivered to the person intending to drink them, the temperature will rapidly tend towards ambient temperature, because the metal from which they are formed will have a high thermal conductivity, as well as being too thin to act as a heat sink in itself.
Insulating means, such as a bag with a drawstring at the neck, are known for keeping cans or wine bottles cool when they are being carried, such as in a haversack or a basket. Also, some external cooling for wine bottles can be provided by a cylindrical jacket of a size to fit tightly over a wine bottle. This jacket can be chilled in the freezer section of a refrigerator and applied over the single bottles for keeping them cool over a short period. Such devices have certain practical shortcomings, however. Although they can be used for carrying cans or bottles before they are opened, they are less useful once the container has been opened, especially a can of the ring-pull type. There will also be a hygiene problem with spillage, which can lead to the inconvenience involved in laundering the container. Moreover, such containers are too expensive for disposable use.
The present invention relates to a container for liquids, said container comprising a shell (preferably formed from a metal) for containing the liquids, wherein the container is provided with a lining member formed from a plastics material having closed cells and providing thermal insulation properties.
In one embodiment, the container can be provided with a means for opening, and then resealing, such as a screw cap.
In another embodiment, the container can be operable but without means for resealing it; such a container could be a ring-pull can.
According to one embodiment of the invention, the lining member is provided by a closed cell member having such dimensions as to fit within the shell and in contact with the internal walls of the shell. For instance, in a ring-pull can, such as is conventionally used for soft drinks, beer, etc., the lining member may be substantially cylindrical, and adapted to provide a slidable fit within the shell so as to be in contact with the cylindrical interior of the shell wall. If desired, this lining member may have an adherent surface to enable the member to adhere to the wall of the can. Such a lining member may be formed from a plastics material having large cells, containing a gas, the material being similar to the wrapping material commonly known as bubble wrap.
In an alternative embodiment, a closed cell material can be provided as a layer on the intended-interior surface of the metal to be used to form the can, in addition to or in place of the conventional lacquer coating applied to the intended interior wall of the can.